See Also

So you decide to drive home after a few drinks. All of a sudden, panic strikes when blue and red lights appear in your rearview mirror.

Getting pulled over is a scary ordeal — even if you haven't had a sip of alcohol. And if you have, a big decision awaits you you: whether or not to take a breathalyzer.

We asked Martin Kron, a New York State traffic attorney and former judge, what to do when facing the threat of a driving under the influence (DUI) charge. (Some states use the acronym DWI, for driving while intoxicated.)

First, most states have "implied consent," Kron said. By getting your license, you also agree to take a breathalyzer upon request. And if you turn it down, many of those states impose a separate penalty where you'll lose your license for a period of time anyway.

In New York, for example, the punishment for refusing a breathalyzer is just as harsh as actually driving drunk, according to Kron. (When you refuse a breathalyzer for the first time in the Empire State, your license can get suspended for a whole year.)

And just because you refused the breathalyzer doesn't mean you successfully avoided a charge. "There are lots of ways a cop can come to the conclusion that you're drunk," Krone explained.

For example, an officer could testify in court that he or she smelled "alcoholic beverage" (since alcohol doesn't have a scent) in the vehicle or that the driver failed a number of field sobriety tests, like walking a straight line or reciting the alphabet.

Technically, the apparatus you blow into on the side of the road isn't even a breathalyzer. It's an alco-sensor, according to Kron, which gives the officer a "loose reading" of your blood alcohol content (BAC). That signals to the officer whether you're within a range that requires going back to the station for a true breathalyzer, which usually occurs in a room with cameras. Your true BAC could increase or decrease by then.

These alco-sensors can malfunction. If you take the test, "you'll give your lawyer something to work with — maybe he can prove the machine wasn't working properly or the cop didn't administer it properly on the scene," Kron said. And you might not even blow above the legal limit. You'll never know unless you try.

There's only one instance where you shouldn't take a breathalyzer — "if you're really, really, really plowed," Kron said. Some states include a drunk driving provision called "aggravated DWI," when you blow .18 or above, which is more than two times the legal limit. Serious penalties accompany aggravated DWI.